Swiss side FC Sion will learn their fate in their battle with UEFA by December 23, the Court of Arbitration for Sport have announced.

Sion have long been fighting UEFA's decision to expel them from the Europa League for fielding five ineligible players in their two-legged play-off with Celtic, believing a FIFA-imposed transfer embargo had expired.

The decision has progressed through the Swiss courts and CAS will make the final judgement in a call which could have implications on Europa League Group I, which features Celtic, Rennes, Udinese and Atletico Madrid.

"The arbitral panel, composed of the arbitrators Mr Patrick Lafranchi, Mr Jean Gay and Mr Hans Nater, president, appointed by the first two arbitrators, will deliver its decision on or before December 23, 2011."

Meanwhile, UEFA have fined Zenit St Petersburg 50,000 euros for crowd incidents at two group stage matches of the Champions League.

A statement from European football's governing body on www.uefa.com, read: "The Russian club were fined for the setting off of fireworks, illicit banners, insufficient organisation and a pitch invasion. "The punishments relate to Zenit's Group G home games against FC Shakhtar Donetsk on November 1 and against APOEL FC on November 23.

"Appeals may be lodged against the verdicts of the UEFA control and disciplinary body within three days of the dispatch of the reasoned decisions."